In order to perform many vascular procedures a guidewire is initially inserted into the patient's vasculature. The guidewire is generally inserted into the patient through an incision created in the patient's femoral artery. After the guidewire has been placed within the patient's vasculature, other interventional devices, such as catheters, maybe be passed over the guidewire. As used herein, the term “interventional device” is intended to include, but not be limited to, any known devices capable of being inserted within the human vasculature for diagnosis, treatment or inspection thereof. Additionally the terms “catheter” and “guidewire” as utilized herein are intended to be interchangeable when referring to the medical device in accordance with the present invention.
One difficulty associated with this procedure however is that the guidewire must be held in place while the interventional device is passed over the guidewire. It is possible that the guidewire may become dislodged from the position where it was initially placed, therefore when a interventional device is advanced over the guidewire it may not be advanced to the desired position.
A common medical procedure where it is desirable to place a guidewire and then advance interventional devices over the guidewire are angioplasty and/or bypass procedures. In an angioplasty procedure, the guidewire may be advanced up to or through a blockage in a patient's vessel, wherein a catheter containing a stent or other interventional device is then passed over the guidewire to the occluded area.
A common procedure performed on occluded or narrowed vessels is to place an angioplasty catheter having a balloon disposed on one end within the occluded region and expanding the balloon, thereby expanding the vessel. The balloon catheter is typically formed of a flexible material wherein the catheter includes radiopaque markings thereon in order to properly place the balloon within the desired region. The balloon catheter is placed within the patient's vasculature through a percutaneous access site such as the femoral artery. The balloon catheter is placed within the patient's vasculature by tracking the catheter over a guidewire which has been placed first. The guidewire enables a user to more easily track the flexible catheter into a proper position, wherein the balloon may be inflated to expand the vessel and/or occlusion therein.
Another commonly utilized cardiovascular procedure is stenting. Stenting is a procedure wherein a expanding device is placed within an obstructed vessel in order to hold open or expand the constricted vessel. Stenting procedures are carried out in a manner similar to the balloon angioplasty procedure described above. Many times both procedures will be performed wherein the vessel may be first expanded with a balloon catheter and subsequently a stent will be deployed thereafter to maintain the expanded diameter of the vessel.
During stenting and/or balloon angioplasty procedures there is the risk that plaque or other debris may be dislodged from the inner walls of the vessel. The plaque may be in the form of small particles which may be carried within the patient's blood stream and may lead to other complications such as embolism if the particles become lodged into a branch vessel or artery and restrict or prevent blood flow to that vessel or artery.
Therefore it is desirable to provide a device which may be utilized during a medical procedure such as those described above wherein the device may be utilized to prevent dislodged particles from flowing into a patient's blood stream and potentially causing further blockage or a stroke. It is also desirable to provide a device which may be utilized to temporarily occlude a vessel distal an area where a surgical procedure is to be performed thereby providing a contained area for the surgeon to operate within.
One such device has been disclosed in U.S. Pat. No. 5,807,330 to Teitelbaum, the entirety of which is incorporated by reference herewith. However, there remains a desire for an improved low profile valve for the device of Teitelbaum.
A further object of the present invention therefore is to provide a medical device having a low profile valve means disposed on the proximal end portion, wherein the valve may be selectively opened and closed thereby enabling the inflation and deflation of a balloon disposed at the distal end portion of the device. Furthermore, the valve provides a sufficiently low profile area wherein other interventional devices may be passed over the medical device to conduct surgical procedures within the patient's vasculature.
A further object of the present invention is to provide a medical device wherein balloon disposed upon the distal end portion of the device may be selectively inflated or deflated through a valve means wherein the inflation device is removable from the valve means.